Request denied by Watchguard http proxy, Connection Untrusted

I type netflix in directly as the location or I click on the link via Google. Either way, it brings up a screen saying "Request denied by Watchguard HTTP Proxy". It gives aReason, Method, Host, Path and then the Override destination (Netflix.com). There is a space to put in an "Override Password". I put in my password for netflix and it directs me to a screen that says:

"This Connection is Untrusted"

You have asked Firefox to connect securely to 10.0.0..., but we can't confirm that your connection is secure. Normally, when you try to connect securely, sites will present trusted identification to prove that you are going to the right place. However, this site's identity can't be verified.
What Should I Do?
If you usually connect to this site without problems, this error could mean that someone is trying to impersonate the site, and you shouldn't continue.